High strength, flexible, foldable printable sheet technique

ABSTRACT

A high strength, flexible, foldable and printable sheet, such as a label sheet or cardstock, is provided with a line of weakness. The sheet has maximum dimensions greater than that of a box into which the sheet is to be located, and is therefore folded flat to fit into the box. The sheet is later removed, and may be printed in a laser or ink jet printer or copier. The sheet is formed to have a tensile strength of at least 4.5 or 5.0 or more kilograms, across the line of weakness, so that it will reliably feed through an office type printer or copier.

This invention relates to printable sheets which are to be folded flatand, following extended storage, may be unfolded and reliably printed.

BACKGROUND OF THE INVENTION

Certain types of children's book, game, or toy products may include cardstock or label sheets, such as 8½×11-inch sheets or A-4 size sheetswhich are stored in boxes for substantial periods of time, and thenprinted in a laser or ink jet printer. Typical size boxes for thechildren's products are 10¼×9×1¾ inches, or 9½×8×1½ inches, for specificexamples; and they are often not large enough to take a normal8½×11-inch (or A-4 size) card stock or label sheet, with the sheetslying flat.

Commercially available card stock and label sheets may be folded, andsome label sheets even have perforations extending through both the facestock and the “liner” or release coated backing sheet. However, whenconventional label sheets are folded to fit into boxes, such as thosementioned above, they may not have sufficient flexibility to easily befolded flat. Further, a number of conventional label sheets or cardstock sheets may be included in children's products and firmly foldedflat and compacted to fit into the box. In addition, they may be storedfor long periods of time. Following this sequence of events,conventional sheets of these types may not have sufficient flexibilityto be unfolded and then have sufficient strength to be reliably printedin a laser printer or an ink jet printer.

Thus, on the one hand, conventional label sheets with transverseperforations through both the face stock and the release coated backingmay initially not easily fold as flat as would be desirable; and then iffolded very flat and held flat for substantial periods of time, thelabel sheets may be creased or may tear at the perforation line, andtherefore not reliably feed, as full sheets, through laser or ink jetprinters.

SUMMARY OF THE INVENTION

One object of the present inventor is to provide a label sheet which mayreadily be folded extremely flat for extended periods of time, and whichmay subsequently be unfolded and reliably printed in an ink jet or laserprinter. Another object of the invention is to provide a label sheetwhich may be reliably printed, and subsequently folded fully flat forinclusion in a product package.

In accordance with one illustrative example of the invention, theforegoing object may be achieved by the use of a label sheet assembly,including a face stock layer and a release coated backing for linerlayer, with pressure-sensitive adhesive between the two layers, and witha fold line formed in the assembly along perforations in the liner, andwith a narrow strip of the face stock being removed over the fold line.

A corresponding method includes the step of folding one or more of thelabel sheet assemblies as described in the foregoing paragraph, foldingthem to place them in a box suitable for selling a product, includingthe sheet assembly or assemblies, and subsequently opening the boxes,unfolding the label sheets, and using a laser or ink jet printer toprint on the unfolded label sheets.

In accordance with a further aspect of the invention, a label sheetassembly including a face stock layer and a release coated backinglayer, with an intermediate layer of pressure-sensitive adhesive, may beprovided with a high-strength, highly flexible fold line so that thelaminated sheet may be readily folded fully flat but may be unfolded foreasy feeding through a laser or ink jet printer before and/or afterfolding.

In the development of the invention, it was found that certain types ofperforations would weaken the sheets of labels or card stock unduly,when the sheets were folded along the perforation lines, and thenunfolded for printing. When the unduly weakened sheets were fed througha printer, the sheets would sometimes separate at the fold lines, or thelabel face stock would come loose from the release coated backingsheets, so as to jam the printer or copier.

To determine the degree of weakening, the invention used anelectromechanical tensile testing machine identified as an INSTRON 4301tensile testing machine, available from Instron Company, 100 RoyallStreet, Canton, Mass. 02021. With the sheets being gripped on oppositesides of the line of weakness, the force required for separating thesheet along the line of weakness, is measured.

Using the tensile strength testing machine, various types of card stockand label sheet perforations were tested following folding andunfolding, and the results of the tests were related to the subsequentsuccess and jamming of copier or laser or ink jet printer action withthe sheets under consideration. One currently popular type ofperforations is known as microperforations, using ties which are lessthan 0.01-inch in width. The cuts between the ties may range from about⅛-inch to less than 0.01-inch. These microperforations formed a weakenedline across a sheet which was greatly weakened by a fold along theperforations, so that the sheets required less than 1 or 2 kilograms offorce for separation, and these weakened sheets did not print reliablyfollowing folding and unfolding.

Label sheets using a backing sheet or liner such as 50-pound releasecoated liner stock were also tested. When the designation “50-poundstock” is used, reference is made to the weight of 500 sheets of paper,26 inches by 36 inches in size. The liner was made by Boise and coatedby Rhinelander. The backing sheet was perforated using 1/16-inch cutsand 1/16-inch ties. A narrow strip of the label face stock extendingover the perforations in the liner was removed. The liner was veryflexible and could easily be folded flat in either direction. Followingfolding, the sheet had a strength of about 18.5 kilograms across theline of perforations. These label sheets reliably feed through copiers,laser printers, and ink jet printers following folding flat andsubsequent unfolding.

Tests were also conducted using label sheets having specifications asset forth above, without removing a strip of face stock. In this case,the line of weakness involved perforations in which the cuts were3/32-inch long and the ties were 1/32-inch in length, through both theface stock and the liner. Following folding and unfolding, theperforated sheet had a strength of about 5.2 kilograms to about 6.6kilograms. Reliable printing and copying resulted, using this labelstock.

Card stock referenced as 100-pound text stock was similarly perforatedusing 3/32-inch cuts and 1/32-inch ties, with similar tensile strengthand favorable copying results, following folding and unfolding.

Tests were made using other sheet perforations. In general, in order tohave reliable printing, the tensile strength along the weakened line wasabove 4.5 kilograms, and was preferably above 5.0 kilograms.

In accordance with a preferred method of the invention, therefore,sheets of label stock or card stock are perforated or otherwise weakenedalong a fold line to increase flexibility, but with adequate ties orresidual sheet material to provide a tensile strength of at least 4.5 or5.0 kilograms after folding flat and subsequent unfolding. The sheetsare folded flat, placed in a box, and are subsequently printed with thesheets unfolded.

Accordingly, the sheets must have sufficient flexibility that theyreadily fold very flat, for inclusion in the boxes mentioned above and,following unfolding, have the levels of strength mentioned above.

The sheets may be card stock or label sheets, including face stockadhesive and release coated backing. Further, as noted above, a strip ofthe face stock may be removed along the fold line to increaseflexibility.

Other objects, features and advantages of the invention will becomeapparent from a consideration of the following detailed description, andthe accompanying figures.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a diagrammatic showing of a label sheet, with one of thelabels in the process of being removed from the sheet;

FIG. 2 is a top plan view of a laminated label sheet with a series ofcircular die-cut labels, and with a narrow strip having been removed ata fold line extending across the sheet;

FIG. 3 is a partial cross-sectional view taken along lines 3—3 of FIG.2;

FIG. 4 indicates schematically the removal of a label sheet which hasbeen folded, from a box;

FIG. 5 shows a printer through which the unfolded label sheet of FIG. 4is fed in order to be printed; and

FIG. 6 is a cross-sectional view of an alternative embodiment of theinvention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring more particularly to the figures, FIGS. 1-3 show a label sheet12 including a top face stock sheet 14, and a bottom release coatedbacking sheet 16. As best shown in FIG. 3, a layer of pressure-sensitiveadhesive 18 is provided between the face stock 14 and the release coatedbacking 16. In FIG. 1, one of the pressure-sensitive labels 20 is shownbeing removed from the laminated sheet 12. In FIG. 1, the circular line22 represents the die cut through the face stock, but not through therelease-coated backing sheet. Incidentally, the backing sheet 16 isnormally coated with a thin release layer of a material such assilicone, so that upon removal of the label, as shown in FIG. 1, thepressure-sensitive adhesive 18 will adhere to the label, and willrelease from the backing sheet.

FIG. 2 is a top plan view of the sheet 12 showing the die cut labels 20.Also shown in all of FIGS. 1, 2 and 3 is the line of weakness 24 whichpermits folding of the label sheet to more easily fit into a box havingmaximum dimensions which are less than the size of the sheet. As shownin FIGS. 1, 2, and 3, the line of weakness includes perforations 26which extend through the release-coated backing sheet 16, and alsoinvolves the removal of a strip of the face stock 14 extending acrossthe sheet so as to permit easier folding about the line of perforations26 in the backing sheet. The dash dot lines 28 in FIG. 3 indicates therelative ease with which the two portions of the sheet 12 may be bentabout the line of weakness 24. Also shown in FIG. 3 are the die cutlines 22 extending through the face stock, but not through the releasecoated backing sheet. Incidentally, in the cross-sectioned views, thethickness of the layers is exaggerated in order to bring out moreclearly the details of the constructions.

Referring now to FIG. 4, a label sheet 12′ is shown having been removedfrom the box which includes the main box portion 34 and the lid 36. Asmentioned above, typical size boxes for children's products are10¼″×9″×1¾″, or 9½″×8″×1½″, for specific examples. Of course, withnormal label sheets being 8½ inches×11 inches in size, they must befolded in other to fit flat in the box 34, 36. Similarly, A4 paper,which is nearly the same size as the 8½″×11″ size sheets, will not fitwithin the boxes under consideration, without folding.

Several of the label sheets, such as label sheet 12, are folded veryflat and included in boxes such as the box 34, 36, along with otheritems making up a game or toy package. Following removal of the labelsheets, they may be fed through a printer or copier such as that shownat reference numeral 38 in FIG. 5, with the label sheet 12″ being readyfor insertion into the printer or copier.

FIG. 6 is a partial cross-sectional view of an alternative label sheet42 including a face stock sheet 44 and a release coated backing sheet 46separated by pressure-sensitive adhesive layer 48. The weakened foldline for the sheet 42 is accomplished by a line of perforations 50 whichextend across the sheet in a manner similar to the line of weakness 24in FIG. 2. However, in the embodiment of FIG. 6, both the face stock andthe release-coated backing sheet are perforated together, and no stripof the face stock is removed, as in the showing of FIGS. 1 through 3. Itmay also be noted that the die cuts 52, as shown in FIG. 6, permit theready separation of labels from the backing sheet. The perforations 50may involve 3/32 inch cuts and 1/32 inch ties, as mentioned above, orother combinations of cuts and ties, providing sufficient flexibility sothat the sheets may be folded fully flat, and then have at least 4.5 to5 or more kilograms of strength, so that they will reliably feed througha copier or printer.

In the foregoing specification, certain specific embodiments of theinvention, and certain specific constructions have been disclosedrelative to the size and construction of the laminated label sheets, andthe nature of the line of weakness. It is to be understood thatvariations in the type of sheets which may be used, and in the nature ofthe lines of weakness, are contemplated. Thus, in addition to thespecific dimensions and the size of the cuts and ties for perforations,other combinations of cuts and ties, or other weakening configurationswhich provide the necessary flexibility and strength as disclosed hereinmay be employed. Thus, for example, but not of limitation, instead ofperforations, the sheets may be die cut partially through the thicknessof the sheets to provide the same flexibility and strength parameters asdiscussed hereinabove. Also, sheets 8½ inches by 14 inches may be used;and, more generally, any sheet material having a maximum dimensiongreater than that of the box or container for the sheets, may be used.Accordingly, the present invention is not limited to the specificembodiments and dimensions disclosed hereinabove.

1. A method comprising the steps of: preparing a discrete label sheetassembly having a width size of approximately one of 8½ inches, and alength of approximately by 11 inches, said and A4, the label sheetassembly including label face stock, pressure-sensitive adhesive and arelease-coated backing sheet, said the sheet being provided with havinga high-strength, high-flexibility fold line extending across the widthof said the sheet assembly; said the fold line including perforations insaid the backing sheet having substantially equal length cuts and ties,and said the face stock having a narrow strip encompassing said the foldline removed from said the assembly; folding said the label sheetassembly along said the fold line; placing said the sheet assembly in abox having a maximum dimension less than 11 inches; removing said thefolded label sheet assembly from said the box; and printing onto saidthe label sheet assembly in an ink jet printer or a laser printer;wherein the sheet assembly is prepared so as to have a tensile strengthacross the perforated fold line of at least 4.5 kilograms.
 2. A methodas defined in claim 1 including the further step of applying printedlabels to additional material provided in said the box.
 3. A method asdefined in claim 1 wherein the sheet is prepared so as to have a tensilestrength across the perforated fold line of at least 4.5 kilograms.
 4. Amethod comprising the steps of: preparing a printable sheet having awidth size of approximately one of 8½ inches, and a length ofapproximately 11 inches, said by 11 inches, 8 1/2 inches by 14 inches,and A4, the sheet being provided with a weakened high-strength,high-flexibility fold line extending across the width of said the sheetassembly ; said the sheet having a tensile strength across said theweakened fold line following folding and unfolding of at least 4.5kilograms; said the weakened fold line providing sufficient flexibilityto permit folding said the sheet flat along said the fold line; foldingsaid the sheet along said the fold line; placing said the folded sheetin a box having a maximum dimension less than 11 inches; removing saidthe sheet from said the box; and printing onto said the sheet in an inkjet printer or a laser printer; wherein the printable sheet is preparedas a label sheet having face stock, a release coated backing sheet, andlayer of pressure-sensitive adhesive between the face stock and thebacking sheet; and wherein the sheet is prepared by including the stepof removing a strip of the face stock along the fold line.
 5. A methodas defined in claim 4 wherein said printable sheet is prepared as alabel sheet having face stock, a release coated backing sheet, and alayer of pressure-sensitive adhesive between the face stock and thebacking sheet.
 6. A method as defined in claim 5 wherein said sheet isprepared by including the step of removing a strip of said face stockalong said fold line.
 7. A method comprising the steps of: preparing adiscrete label sheet assembly having a predetermined width and apredetermined length, said the label sheet assembly including label facestock, pressure-sensitive adhesive and a release-coated backing sheet;said the sheet being provided with having a high-strength,high-flexibility fold line extending across the width of said the sheetassembly; said the fold line including perforations in said the backingsheet having substantially equal length cuts and ties, and said the facestock having a narrow strip encompassing said the fold line removed fromsaid the assembly; folding said the label sheet assembly along said thefold line; placing said the folded label sheet assembly in a box havinga maximum dimension less than said the predetermined length; removingsaid the label sheet assembly from said the box; and printing onto saidthe sheet in an ink jet printer or a laser printer; wherein the sheet isprepared so as to have a tensile strength across the perforated foldline of at least 4.5 kilograms; and including the further step ofapplying printed labels to additional material provided in the box.
 8. Amethod as defined in claim 7 including the further step of applyingprinted labels to additional material provided in said box.
 9. A methodas defined in claim 7 wherein the sheet is prepared so as to have atensile strength across the perforated fold line of at least 4.5kilograms.
 10. A method comprising the steps of: preparing a printablesheet having a predetermined width and a predetermined length, saidsheet being provided with a weakened high-strength, high-flexibilityfold line extending across the width of said sheet assembly; said sheethaving a tensile strength across said weakened fold line followingfolding substantially flat and unfolding, of at least 4.5 kilograms;said weakened fold line providing sufficient flexibility to permitfolding said sheet flat along said fold line; folding said sheet alongsaid fold line; placing said folded sheet in a box having a maximumdimension less than said predetermined length; removing said sheet fromsaid box; and printing onto said sheet in an ink jet printer or a laserprinter.
 11. A method as defined in claim 4 wherein said printable sheetis a label sheet having a face stock, a release coated backing sheet;and an intermediate layer of pressure-sensitive adhesive.
 12. A methodas defined in claim 11 wherein said sheet is prepared by including thestep of removing a strip of said face stock along said fold line.
 13. Amethod as defined in claim 11 wherein said method includes preparing thesheet approximately 11 inches in length.
 14. A method comprising thesteps of: preparing a printable sheet having a predetermined width and apredetermined length, said sheet being provided with a weakenedhigh-strength, high-flexibility fold line extending across the width ofsaid sheet assembly; said sheet having a tensile strength across saidweakened fold line following folding and unfolding of at least 4.5kilograms; said weakened fold line providing sufficient flexibility topermit folding said sheet flat along said fold line; folding said sheetalong said fold line; placing said folded sheet in a box having amaximum dimension less than said predetermined length; removing saidsheet from said box; and manipulating said sheet without separating thesheet along said lines of weakness.
 15. A method as defined in claim 14wherein said printable sheet is prepared as a label sheet having facestock, pressure-sensitive adhesive and a release coated backing sheet.16. A method as defined in claim 15 wherein said sheet is prepared byincluding the step of removing a strip of said face stock along saidfold line.
 17. A method as defined in claim 14 including the step ofprinting on said sheet following removal from the box and unfolding. 18.A method as defined in claim 14 including the step of printing on saidsheet before placing the sheet in said box.
 19. A method as defined inclaim 14 wherein said preparing step includes forming said fold line tohave a strength across said fold line of at least 5.0 kilograms.
 20. Amethod comprising the steps of: preparing a discrete label sheetassembly having a size of one of 8 1/2″ by 11″, 8 1/2″ by 14″ and A4,the label sheet assembly including label face stock, pressure-sensitiveadhesive and a release-coated backing sheet, the sheet having ahigh-strength, high-flexibility fold line extending across the width ofthe sheet assembly; the fold line including perforations in the backingsheet having substantially equal length cuts and ties, and the facestock having a narrow strip encompassing the fold line removed from theassembly; folding the label sheet assembly along the fold line; andplacing the sheet assembly in a package having a maximum dimension lessthan 11 inches; wherein the fold line has a strength of at least 4.5kilograms.
 21. A method as defined in claim 20 further comprising thesteps of removing the label sheet assembly from the package, unfoldingthe label sheet assembly and printing on the label sheet assembly.
 22. Amethod as defined in claim 20 wherein the package is a box.
 23. A methodcomprising the steps of: preparing a discrete printable sheet having asize of one of 8 1/2″ by 11″, 8 1/2″ by 14″ and A4, the sheet beingprovided with a weakened high-strength, high-flexibility, perforatedfold line extending across the width of the sheet; the sheet having atensile strength across the weakened fold line following folding andunfolding of at least 4.5 kilograms; the weakened fold line providingsufficient flexibility to permit folding the sheet flat along the foldline; inserting the sheet after folding into a separate package having amaximum dimension less than 11 inches; wherein the printable sheet isprepared as a label sheet having face stock, a release coated backingsheet, and a layer of pressure-sensitive adhesive between the face stockand the back sheet; and wherein the sheet is prepared by including thestep of removing a strip of the face stock along the fold line.